Answer: I don't. I don't care what other people believe about God or not-God or clouds in the sky or fish in the sea. Zeus? Neptune? The great flying spaghetti monster? Or nothing at all? Go for it. I don't care, by which I mean, I don't judge you for your beliefs.
As Jeff and I talked about hummingbirds' feet or lack thereof, we realized that a lot of old-time beliefs and superstitions can be explained by the lack of that essential part of the scientific method: information. If you are missing essential information, your conclusions are bound to be incorrect.
So, you make a hypothesis, backed up by initial observations: because you don't see any feet on the hummingbirds you see flying around, many meters away from you, and you never see them landing or perching on anything, and these hummingbirds are remarkably different from all the other birds you've been watching all your life, you draw an obvious conclusion: they must not have feet.
Or, let's say, one day a black cat crosses your path as you're walking down the street, and right after that you get run over by a horse-drawn cart. Obvious conclusion: black cats bring bad luck, whether you were so busy watching the cat that you weren't paying attention to the street traffic or not.
Or, let's say, you walk under a ladder which proceeds to fall on you. Obvious conclusion: walking under a ladder brings bad luck.
And so on. Pass these beliefs on to your kids, and, sure enough, they walk way out of their way to avoid black cats and ladders, and, miraculously, they remain safe. Case closed.
On the other hand, let's say you are wondering about some idea that had been passed down to you from generations before, wondering because you've made some observations that seem to contradict that idea. You use the scientific method.
For instance, what about the notion of spontaneous generation? Check out some notions related to this idea, thanks to Net Industries:
Spontaneous generation, also called abiogenesis, is the belief that some living things can arise suddenly, from inanimate matter, without the need for a living progenitor to give them life.
In the fourth century B.C., the Greek philosopher and scientist Aristotle argued that abiogenesis is one of four means of reproduction, the others being budding (asexual), sexual reproduction without copulation, and sexual reproduction with copulation. Indeed, the Greek goddess Gea was said to be able to create life from stones.